 (defn make-default-machine [] { :stock {:caramel-wafer 5 :teacake 5 :snowball 5}
 	:coins {:merk 1 :plack 4 :bawbee 4 :bodle 4}
 	:tendered nil
-	:last-message ""
+	:message ""
 	:change nil
 	:output nil} )
 

  "Given this amount of change to make, and this number each of merks, placks, bawbees
  and bodles, return a tuple (merk plack bodle bawbee) which indicates the number remaining
	after making change, or nil if not possible"
  (print (list "in-make-change:" amount merk plack bawbee bodle))
	(cond
		(= amount 0) (list merk plack bawbee bodle)
		(and (>= amount (:merk coin-values)) (> merk 0))

  "Sum the value of these coins."
	(apply + (map coin-value coins)))


(defn message-machine [machine message]
  "Return a machine with this message"
  (assoc (dissoc machine :message) :message (.toString message)))

(defn coin-return [machine]
  "Return all tendered coins in this machine."
	(message-machine (assoc (dissoc machine :tendered) :change (:tendered machine)) "Coins returned"))

(defn add-coin [machine coin]
  "Add this coin to this machine."
	(message-machine (assoc (dissoc machine :tendered) :tendered (cons coin (:tendered machine))) (str "Added a " coin)))

(defn add-coins [machine coins]
  "Add these coins to this machine"
